Officials compared the marketplace discovered by “Operation Babylon” to the Silk Road online black market that was taken down by the U.S. Federal Bureau of Investigation in 2013.

More than 14,000 people had signed up to the illegal community, which was allegedly run by an Italian living near Naples. There was evidence of 170,000 transaction messages on the Tor platform, which provided 12 kinds of hidden services, police said. These ranged from pornographic images to arms, drugs, false identity papers, hacker kits and credit card codes.

The site hosted around 210 drug dealers, including a notorious operator who uses the pseudonym “Pablo Escobar” after the late Colombian drug lord.

“The virtual world of the Dark Web has its own hierarchies and severe rules on access and affiliation. Getting into such a closed community was extremely difficult,” Michele Prestipino, a public prosecutor who coordinated the investigation, told a press conference in Rome.

Dark Web sites do not show up on normal search engines, and the Italian site provided detailed instructions to help users screen their identities.

Police officers working undercover succeeded in penetrating the illegal community in a two-year operation that began as an investigation into the online exchange of child pornography.

Italian investigators have been cooperating with Europol, the European Union’s law enforcement agency, and the FBI, to identify customers and sellers who connected on the Italian-operated platform.

Prestipino said the inquiry had been a new experience for Italian law enforcement, revealing the existence of an “incredible criminal world, parallel to Internet, which paradoxically represents only a small part of the communications taking place over the Web,” he said. “For us this investigation is just a point of departure.”

To comment on this article and other PCWorld content, visit our Facebook page or our Twitter feed.